Now that I have had a full 8+ hours of using the new design interface, here are my top take aways ...
1: I like the Properties Panel changes. Everything makes sense and having the proper theme colors really helps. Well done there.
2: The Quick Access Menu needs some sort of sorting or logical order. The menu options are all over the place.
3: Building forms manually is now extra work and not very intuitive at all. A step backwards.
4: Data Detail Regions is busted. See bug report.
Overall, I think the changes are in the right direction although it took some getting used to. Great work so far guys. Wappler 5 is fun to work with. Maybe I'll find more tomorrow but so far it looks good.